如图是一个血友病遗传系谱图,从如图可以看出患者7的致病基因来自( ) A.1 B.4 C.1和3 D.1和4 答案:解:从题意和图可知,血友病是伴X染色体上隐性遗传病,女性患病亲代男性患病,女性至少为致病基因携带者,这个才能各为子代女性提供一个致病基因,6的基因来自于3,5的基因只能来自于1,所以患者7的致病基因来自1和3. 故选:C.Mother was worried because little Alice was ill, especially ________ Father was away in France.
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A.asB.that
C.duringD.if